HLA class I histocompatibility antigen, A-24 alpha chain (HLA-A24) (HLA-A24)

HLA class I histocompatibility antigen, A-24 alpha chain (HLA-A24) is a critical component of the major histocompatibility complex (MHC) class I system, essential for the adaptive immune response (UniProt, 2024). It functions by binding and presenting peptide fragments from intracellular proteins on the cell surface for recognition by CD8+ cytotoxic T lymphocytes (PubMed: 10449296, PubMed: 28250417). This molecule is particularly significant due to its high frequency in East Asian and Indigenous populations, which influences the design of population-specific immunotherapies (Wikipedia, 2024; ResearchGate, 2020). In oncology, HLA-A24 is a major target for peptide vaccines and TCR-engineered T-cell therapies that aim to present tumor-associated antigens, such as WT1 or MUC1, to the immune system (PMC: 17189421, NCI, 2025). Conversely, the HLA-A*24:02 allele is a critical pharmacogenomic biomarker associated with severe drug-induced hypersensitivity reactions, such as Stevens-Johnson syndrome (PubMed: 28588054). Drugs like carbamazepine and lamotrigine can interact with HLA-A24 to trigger these life-threatening immune responses in susceptible individuals (PubMed: 28588054, Cochrane Library, 2020). Therapeutic challenges include tumor immune evasion through the loss of HLA expression and the need for precise patient stratification based on HLA genotype (PMC: 6359184). Overall, HLA-A24 is a dual-purpose target in modern medicine, serving as both a vehicle for immunotherapy and a safety marker for drug development.

Other names

HLA-A*24HLA-A*24:02MHC class I antigen A*24HLA-A9Human leukocyte antigen A24

HLA-A24 presents intracellularly processed peptide antigens to the T-cell receptors (TCR) of CD8+ cytotoxic T lymphocytes, thereby initiating an adaptive immune response against infected or malignant cells (UniProt, 2024). In drug hypersensitivity, certain drugs or their metabolites interact with the HLA-A24 molecule or the peptide-HLA complex to trigger an off-target T-cell mediated immune reaction (PMC: 5489392).